For many years, automobiles have employed electric lighting that serves a variety of functions. For instance, lights provide forward illumination (headlamps, auxiliary lamps), conspicuity (parking lights in front, taillights in rear), signaling (turn signals, hazards, brake lights, reversing lights), and convenience (dome lights, dashboard lighting), to name only a few applications. In recent years, light emitting diodes (LEDs) have become common in some of the lighting applications for automobiles. Compared with older incandescent bulbs, LEDs use less power, last longer, and have less heat output, making them well suited for automotive applications.
There is an ongoing effort to incorporate LEDs into fog lamps, as well as an ongoing effort to reduce the cost of manufacturing and simplify the assembly of fog lamps.
Some known lenses that incorporate total internal reflection (TIR) and some known fog lamps are disclosed in U.S. Pat. No. 8,011,803 (Cheung et al.), U.S. Patent Application Publication No. 2008/0043466 (Chakmakjian et al.), U.S. Pat. No. 5,404,869 (Parkyn, Jr. et al.) and U.S. Pat. No. 7,686,486 (Tessnow et al.).